Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!mnetor!seismo!rutgers!mtune!mtgzz!rosen
From: rosen@mtgzz.UUCP (t.rosenfeld)
Newsgroups: comp.sys.ibm.pc,comp.lang.c
Subject: Re: Inline assembler in Microsoft C ????
Message-ID: <2800@mtgzz.UUCP>
Date: Mon, 29-Jun-87 13:38:04 EDT
Article-I.D.: mtgzz.2800
Posted: Mon Jun 29 13:38:04 1987
Date-Received: Tue, 30-Jun-87 07:03:03 EDT
References: <608@zen.UUCP> <2299@hoptoad.uucp> <2093@emory.UUCP>
Organization: AT&T, Middletown NJ
Lines: 41
Keywords: Inline assembler code
Xref: mnetor comp.sys.ibm.pc:5171 comp.lang.c:2706

[Sorry for the multiple posting screw up.]

In article <2093@emory.UUCP>, platt@emory.UUCP writes:
> In article <2299@hoptoad.uucp> pozar@hoptoad.UUCP (Tim Pozar) writes:
> >In article <608@zen.UUCP> vic@zen.UUCP (Victor Gavin) writes:
> >>
> >>Can anyone tell me if there is an "inline" assembler capability for this
> >>compiler.
> Having done a fair amount of C/Assembler interfacing (using MS C 4.0)
> I can say that it's not too much of a burden to write the code, and
> link the .obj modules in at link time.  It also gives you more control
> over how and where your data is treated and stored.
> 
> Dan

As Dan writes MS tells you how to interface to assembly routines, but you 
probably would rather have inline code than be forced to do a CALL to
an assembly routine.

As far as I know there is no #asm directive in 4.0 but I think I heard there
will be in 5.0. One way to get around this is to compile your C code and have
the compiler generate the assembly module. (I think this is the -Fs option.)
Then enter your inline assembly at the correct loaction, assemble and link.
Of course if you ever want to edit the C source again you hac=ve to do it all
over again. 

This trick is also usefull to generate the corect compiler
directives to link an assembly function to the rest of your C  program.
That is write a null C funtion (e.g. ass_fun(){}) and then compile
with -Fs and then insert your assembly into the .asm file.

WARNING: When using the MS C 3.0 version in large model mode I ran into
a bug were the .asm file prodused by the -Fs option was wrong. Sometimes
it would not link, or worse yet it would link but the segment registers would
be wrong. I think I found the file was OK except it loaded SS with _DATA
instead of DGROUP.
-- 
Tom Rosenfeld	 	@ AT&T Information Systems Labs, Middletown, NJ
			(201) 957-5867 	
			UUCP:		{harpo,ihnp4,burl,akgua}!mtgzz!rosen
Disclaimer: I don't claim anything.